Many types of measurement and communication systems include a receiver coupled to a signal source through a signal path. Performance of these systems can be limited by amplitude unflatness, group delay variations and other distortion in the receiver or signal path. Calibration schemes, which include determining the frequency response of the receiver or signal path, are used to overcome performance limitations that are attributed to distortion. Known calibration schemes, such as those employed in dynamic signal analyzers, vector signal analyzers and other types of receivers, use the signal source to stimulate the receiver with a known stimulus signal. Response of the receiver to the known stimulus signal is determined and compared to a predicted response to correct for distortion introduced by the receiver. However, when the signal path coupling the source to the receiver introduces distortion to the stimulus signal, the accuracy of this calibration technique relies on both the accuracy with which the stimulus signal is known and the accuracy with which the signal path can be characterized. There is a need for a response calibration method that does not rely on accurately determining the characteristics of the stimulus signal and an accurate characterization of the signal path.